Package integrated synthetic jet device

ABSTRACT

Embodiments include a synthetic jet device formed within layers of a package substrate, such as to provide a controlled airflow for sensing or cooling applications. The jet device includes an electromagnetically driven vibrating membrane of conductive material between a top and bottom cavity. A top lid with an opening covers the top cavity, and a permanent magnet is below the bottom cavity. An alternating current signal conducted through the membrane causes the membrane to vibrate in the presence of a magnetic field caused by the permanent magnet. By being manufactured with package forming processes, the jet (1) is manufactured more cost-effectively than by using silicon chip or wafer processing; (2) is easily integrated as part of and with the other layers of a package substrate; and (3) can be driven by a chip mounted on the package. Embodiments also include systems having and processes for forming the jet.

CROSS-REFERENCE TO RELATED APPLICATION

The application is a continuation of co-pending U.S. patent applicationSer. No. 14/728,705, filed Jun. 2, 2015, entitled PACKAGE INTEGRATEDSYNTHETIC JET DEVICE.

BACKGROUND

Field

Embodiments of the invention are related to a synthetic jet deviceformed within or as the layers of a package substrate having layers ofconductive traces, conductive vias, and dielectric material. The jetdevice includes an electromagnetically driven vibrating membrane ofconductive material between a top and bottom cavity. A top lid with anopening covers the top cavity, and a permanent magnet is below thebottom cavity.

Description of Related Art

Traditionally, fans and blowers can be used to create airflow, such asto cool an active electronic device (e.g., transistor or computerprocessor) or to provide a controlled amount of airflow for sensingpurposes. Unfortunately, fans and blowers are very inefficient airmovers when scaling down to very small sizes such as at a millimeter(mm) scale. Thus, a device may be manufactured to deliver relativelylarge flow rates even for these very small scales. However, suchmanufacturing technologies can be time consuming and expensive.Therefore, there is a need for a quickly and inexpensively fabricateddevice to deliver relatively large flow rates for very small scales,such as a mm scale device.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments of the invention are illustrated by way of example andnot by way of limitation in the figures of the accompanying drawings inwhich like references indicate similar elements. It should be noted thatreferences to “an” or “one” embodiment of the invention in thisdisclosure are not necessarily to the same embodiment, and they mean atleast one.

FIG. 1A shows a cross sectional view of a synthetic jet device accordingto embodiments of the invention.

FIG. 1B shows a top view of the synthetic jet device of FIG. 1A.

FIG. 2 shows an embodiment of a system including a synthetic jet deviceaccording to embodiments of the invention.

FIGS. 3A-3H show one example of a package substrate formation processfor forming a synthetic jet device.

FIGS. 4A-4E show a second example of a package substrate formationprocess for forming a synthetic jet device.

FIG. 5 shows a third example of a package substrate formation processfor forming a synthetic jet device.

FIG. 6 illustrates a computing device, such as a system on a chip (SoC),in accordance with some implementations.

DETAILED DESCRIPTION

In the description above, for the purposes of explanation, numerousspecific details have been set forth in order to provide a thoroughunderstanding of the embodiments. It will be apparent however, to oneskilled in the art, that one or more other embodiments may be practicedwithout some of these specific details. The particular embodimentsdescribed are not provided to limit the invention but to illustrate it.The scope of the invention is not to be determined by the specificexamples provided above but only by the claims below. In otherinstances, well-known structures, devices, and operations have beenshown in block diagram form or without detail in order to avoidobscuring the understanding of the description. Where consideredappropriate, reference numerals or terminal portions of referencenumerals have been repeated among the figures to indicate correspondingor analogous elements, which may optionally have similarcharacteristics.

Traditionally, fans and blowers can be used to create airflow, such asto cool an active electronic device (e.g., transistors or a computerprocessor “chip”) or to provide a controlled amount of airflow forsensing purposes (e.g., air quality sensors or resonant sensors).However, fans and blowers are very inefficient air movers when scalingdown to very small sizes such as at a millimeter (“mm”) scale.

According to embodiments (e.g., without restriction thereto), asynthetic jet device may be a preferred choice when in need of largeflow rates, in applications constrained to only mm-scale devices. Suchmm scale devices may include synthetic jet devices that are smaller thana few millimeters (i.e., an example can be 2 mm across, or where anouter perimeter or diameter of the device, such as diameter D3 below isbetween 1 and 3 mm across). Thus, synthetic jets may be a preferredtechnology for delivering controlled flows to sensor locationsespecially in space constrained devices, such as wearables (e.g., labjackets, bracelets, watches), smartphones, tablets, etc. The mm-scalesynthetic jet devices can also provide airflow in very thin air gaps toincrease cooling capacity (e.g., for a computer processor or processorpackage), where airflow has previously not been generated. The pulsatingflow from synthetic jet devices provides a well suited flow to break upthermal boundary layers to create a more uniform temperaturedistribution.

In some cases (e.g., without restriction thereto), a synthetic jetdevice may include a membrane that is free to vibrate in the verticaldirection and is surrounded by cavities on both sides. The top sidecavity may have an orifice or opening through which the flow is suckedin and expelled. A permanent magnet (to be integrated with the package,or attached to the device) may be used to create a magnetic field at thelocation of the membrane. An alternating current (AC) current may thenbe sent through this membrane, creating a Lorentz force that causes themembrane to vibrate up and down. During the downward motion of themembrane, the decrease in pressure in the top cavity causes air to besucked in from the environment. In the upward motion of the membrane,the increase in pressure in the top cavity causes “puffs” of air (e.g.vortices) or fluid to be generated and expelled through the orifice.These puffs may “entrain” or draw along surrounding air along the way,creating a net outflow (e.g., “jet”) away from the orifice. Entrainingthe surrounding air may be caused by the movement of the air of thepuffs pulling air adjacent to the puffs along with and in the samedirection as the puffs. Such synthetic jet devices can be designed tomove or create jets of air, gas or fluid. For example, in someembodiments, instead of air, fluid may be sucked in from the environmentand expelled (e.g., such as by having the cavities of the jet deviceliquid sealed).

In some cases, a synthetic jet device may be manufactured using silicon(e.g., computer processor “chip”) or wafer manufacturing technologies(e.g., wafer based Micro-Electro-Mechanical Systems-MEMS fabricationprocesses) to deliver relatively large flow rates even for these smallscales. However, manufacturing a jet device using these technologies canbe expensive.

According to some embodiments described herein, a computer processorpackage device fabrication technology (e.g., “package technology” suchas using processes known for forming processor package substrates) isused instead of a silicon or wafer manufacturing technology. Packagetechnology may differ from silicon micromachining by using materials(such as copper or organic dielectric) that are less expensive thansilicon, and fabricating large batches of units at a scale (e.g.,20″×20″ panel) that is larger than the 6″ or 8″ wafer scale typicallyassociated with silicon micromachining. This leads to a net low cost perfabricated unit when using package fabrication technology versus siliconmicromachining. The package technology may be used to create jetdevices, by incorporating a package process dielectric etch process(e.g., see FIGS. 3A-5) to create a computer processor package thatincludes the jet device. These package technology embodiments mayinclude mm scale synthetic jet devices (e.g., see FIGS. 1-5) that areinexpensively fabricated in large batches to deliver relatively largeflow rates for small sizes such as devices smaller than a fewmillimeters.

Using package technology (e.g., see FIGS. 3-5) offers significantadvantages over silicon micromachining of jet devices, such as costsavings due to the panel-level nature of substrate package fabricationversus wafer level silicon chip manufacturing, and the absence ofexpensive process such as deep reactive ion etching (DRIE) which arerequired to realize the jet devices in silicon chips. Using packagingtechnology also allows tighter integration with the rest of the system(e.g., see FIG. 2), by not requiring a separate package to house the jetdevice or a separate application-specific integrated circuit (ASIC) dieto drive the device. Instead, the driving circuitry can now be directlyintegrated with the system on chip (SoC) die, such as by beingintegrated into the processor mounted on the package that includes thejet device.

Consequently, some embodiments described herein include a package-basedsynthetic jet device technology to enable delivery of a controlledairflow from the jet device (e.g., see FIGS. 1A-2) by forming asynthetic jet device having a vibrating membrane that is enclosed in acavity, and that has an orifice or opening in its lid. As the membranevibrates, “puffs” of air are expelled through the orifice that entrainsurrounding air and generate an air jet. It can be appreciated that theconcepts herein can be applied to create puffs of a gas (e.g., otherthan air such as oxygen, hydrogen, nitrogen, fluorine, argon, helium andthe like) that entrain surrounding gas and generate a gas jet. It can beappreciated that the concepts herein can be applied to create puffs of aliquid (e.g., such as water, lubricant, oil, coolant, and the like) thatentrain surrounding liquid and generate a liquid jet.

More specifically, FIG. 1A shows a cross sectional view of a syntheticjet device according to embodiments of the invention. FIG. 1B shows asimplified top view of the synthetic jet device of FIG. 1A. FIG. 1 showssynthetic jet device 100 including vibrating membrane 120 disposedbetween top cavity 118 and bottom cavity 114. Vibrating membrane 120 hastop surface 122 and bottom surface 124 which may be planar surfaces,such as surfaces fabricated by electroplating conductor over a layerincluding conductor and insulator during fabrication of a packagingsubstrate. Top surface 122 may form (e.g., may be or may define) thebottom surface of cavity 118 and bottom surface 124 may form the topsurface of cavity 114. In some cases, a cavity, such as cavity 114 maybe a closed in or sealed space, chamber or volume having no openings. Insome cases, a cavity, such as cavity 118 may be a closed in or sealedspace, chamber or volume having only one opening.

Vibrating membrane 120 may be made of a conductive material, such as ametal or alloy. In some cases, vibrating membrane may be made ofconductor such as copper, gold, titanium, silver, or an alloy. Membrane120 may be disposed in or formed as part of a package substrate, such asa package substrate for packaging, or interfacing to a microprocessor,computer processor, chip, or other logic circuitry (e.g., having activedevices (e.g., transistors) and/or resistor, capacitors and diodes) asknown in art. Membrane 120 may be formed by laminating or electroplatingmetal or copper on a layer of dielectric during a chip packagefabrication process. In some cases, membrane 120 is formed as part of apackage substrate, such as during formation of device 100, 301, 401 or501 (e.g., see FIGS. 1-5).

Membrane 120 is shown above (e.g., mounted or formed on) lower support130 and below upper support 140. In some case, membrane 120 is disposedbetween or suspended between (e.g., mounted or formed on) top surfaces132 of lower support 130. In some cases, support 140 may be mounted orformed on membrane 120 (e.g., as shown in FIG. 1A). In some cases,support 140 may represent an upper support that is not mounted or formedon membrane 120 (e.g., as shown in FIGS. 3A-5).

Lower support 130 is shown having top surface 132 attached to (e.g.,physically coupled to or touching) an outer perimeter or diameter ofbottom surface 124. Lower support 130 forms or defines an outer surfaceof cavity 114 below surface 124. Lower support 130 may be formed of aconductive material, such as noted for membrane 120. Lower support 130may be disposed in or formed as part of a package substrate or byelectroplating, such as noted for membrane 120.

Outer perimeter P of surface 124, member 120 or surface 122 may be aring shaped area from a top perspective view (e.g., see P of FIG. 1B)around the outer edge of member 120. In some cases, perimeter P may be awidth or horizontal ring distance of between 3 and 5 percent of thedistance of diameter D1. In some cases, perimeter P may be a width orhorizontal ring distance of between 5 and 10 percent of the distance ofdiameter D1. In some cases, perimeter P may be a width or horizontalring distance between diameter D3 and diameter D1. In some cases,instead of a circular diameter, perimeter P may have an inner perimeteror outer perimeter (or both) that has the shape of an oval, a rectangle,a square, a triangle, a rhombus, a trapezoid, or a polygon. In somecases, the cross sectional area of that shape will be the same asdescribed for the circular diameter (e.g., P).

Upper support 140 is shown in FIG. 1A-B having bottom surface 144attached to (e.g., physically coupled to or touching) an outer perimeteror diameter of top surface 122. Upper support 140 forms or defines anouter surface of cavity 118 above surface 122. Upper support 140 may beformed of a conductive material, such as noted for membrane 120. Uppersupport 140 may be disposed in or formed as part of a package substrateor by electroplating, such as noted for membrane 120.

Permanent magnet 150 is shown having top surface 152 coupled to bottomsurface 132 and forming or defining a bottom surface of cavity 114.Magnet 150 has bottom surface 154. Magnet 150 may have an outerperimeter or diameter of top surface 152 attached by another materialsuch as an adhesive (e.g., not physically coupled to or touching) tobottom surface 134. In some case, this perimeter extends across aportion of the width of magnet 150, similar to the width of perimeter Pdescribed for membrane 120.

Magnet 150 may be formed of or include a ferromagnetic material andproduce a magnetic field, as known in the art. Magnet 150 is showncreating magnetic field B in a direction into the paper of FIG. 1A andas shown in FIG. 1B. Magnet 150 may be formed of a permanently magneticmaterial. Magnet 150 may be formed as part of a package substrateprocess such as by attaching or bonding magnet 150 to surface 134 duringformation of package device (e.g., during formation of device 100, 301,401 or 501). In some cases, magnet 150 does not move or flex verticallywith respect to support 130, while membrane 120 vibrates.

According to some embodiments, feature or component 150 shown in FIGS.1A-B is not a magnet but represents a non-magnetic layer of materialshaped similar to membrane 120, but having a thickness of at least twicethat of membrane 120 (or thick enough not to vibrate or change theoutput during use of the jet device). This layer of material may be alayer of insulator (e.g., dielectric material) shaped similar tomembrane 120. In this case, a separate magnet is provided eitherattached to bottom surface 154 or disposed below surface 154 to create amagnetic field in cavity 114.

Top lid 110 is shown having surface 112 and bottom surface 115 coupledto top surface 142 and forming or defining a top surface of cavity 118.Top lid 110 has top surface 112. In some cases, top lid 110 has an outerperimeter or diameter of bottom surface 115 attached to (e.g.,physically coupled to or touching) top surface 142. In otherembodiments, top lid 110 has an outer perimeter or diameter of bottomsurface 115 attached by another material such as an adhesive (e.g., notphysically coupled to or touching) to top surface 142. When attached byanother material, lid 110 may be formed of an insulator or of aconductive material. The attached outer perimeter may extend across aportion of the width of top lid 110, similar to the width of perimeter Pdescribed for membrane 120.

Top lid 110 is shown having opening 116, such as an opening along thecenter axis C of membrane 120 as shown in FIG. 1B. Opening 116 is shownformed through lid 110, such as extending from surface 112 to surface115 (e.g., forming an opening between surface 112 and 115). Lid 110 maybe formed of an insulating or dielectric material. Lid 110 may bedisposed in or formed as part of a package substrate, such as asubstrate for packaging, or interfacing to, a microprocessor, computerprocessor, chip, printed circuit board, or other logic circuitry asknown in art. Top lid 110 may be a layer of insulator material ordielectric material formed during a process for forming a layer of suchmaterial during a package substrate fabrication process (e.g., see FIGS.3-5). In some cases, lid 110 may be formed by attaching or bonding lid110 to surface 142.

Membrane 120 is shown with height H1, support 130 is shown with heightH2, magnet 150 is shown with height H3, support 140 is shown with heightH4, and lid 110 (as well as opening 116) has height H5. Opening 116 isshown having diameter D2. Lid 110, support 130, support 140, membrane120, and magnetic 150 are shown having outer perimeter or diameter D3.Support 130 and 140 are shown having inner perimeter or diameter D1.Consequently, in FIG. 1A-B cavities 114 and 118 have a diameter D1. Insome cases, the upper support 140, the membrane 120 and the lowersupport 130 are formed of a conductor; and the lid 110 is formed of aninsulator. In some cases, the upper support 140, the membrane 120 andthe lower support 130 are formed of a metal or alloy; and the lid 110 isformed of a dielectric material. In some cases, the upper support 140,the membrane 120 and the lower support 130 are formed of the samematerial; and the lid 110 is formed of solder resist. In some cases, theupper support 140, the membrane 120 and the lower support 130 are formedof copper; and the lid 110 is formed of solder resist. In some cases,the upper support 140, the membrane 120 and the lower support 130 areformed of copper; and the lid 110 is formed of solder resist during apackage formation process that forms layers of a packaging substrateincluding layers of electronic pads, electronic traces, electronic viasand dielectric material.

Some embodiments drive the synthetic jet device (e.g., device 100, 301,401 or 501) electromagnetically, which, at the length scales of packagesubstrates (e.g., 15-30 micron gap heights for cavities 114 and 118), ismore effective than other means of actuation (e.g., better thanelectrostatic or piezoelectric actuation, which would require very highactuation voltages). Driving the synthetic jet deviceelectromagnetically may include causing membrane 120 to vibrate byconducting an alternating current control signal (e.g., Iac) through thevibrating membrane, and having a magnet (e.g., magnet 150) located aboveor below the membrane to provide a magnetic field across the membraneperpendicular to the flow of current, i.e., coming out of the page inFIG. 1A.

In some cases (e.g., without restriction thereto), the resonantfrequency of the membrane may be selected or predetermined (e.g., basedon design of device 100) to keep this frequency above audible frequencylevels (such as above 20 kHz) to achieve “quiet” operation of thesystem. In some cases, the Helmholtz frequency of the upper cavity beselected or predetermined (e.g., based on design of device 100) to keepthis frequency above audible frequency levels (such as above 20 kHz) toachieve “quiet” operation of the system. In some cases, both frequenciesare above the audible frequency level. In other cases, only one orneither frequency is about the audible frequency level. For someembodiments, the operational frequency of the synthetic jet can still beabove 20 kHz even if the membrane natural frequency and/or cavityHelmholtz frequency are not. Operating the jet device above 20 kHz mayresult in “quiet” operation. Designing the membrane and cavity (e.g.,cavity 114 and/or 118) for the same frequency may optimize theperformance (e.g., optimize power and flow).

In some cases (e.g., without restriction thereto), the resonantfrequency of membrane 120 may be selected or predetermined to be lessthan 100 kHz or below 90 kHz. In some cases, the resonant frequency ofthe membrane may be selected or predetermined to be less than 50 kHz. Insome cases, the resonant frequency of the membrane may be selected orpredetermined to be between 30-50 kHz. In some cases, the resonantfrequency of the membrane may be selected or predetermined to be between25-80 kHz. In some cases, the jet device may be inaudible due to itssmall size or puffs 170 (or flow 216) being small enough in volume to beinaudible to a person using a device which houses device 100 or system200.

In FIG. 1A, membrane 120 is shown having vibrational physical amplitude127, such as a maximum distance which a location of the top surface 122of membrane 120 will travel or flex in the upward and downwarddirections during use or actuation of membrane 120. Membrane 120 may beactuated by electromagnetic force or excitation by running analternating current through membrane 120, such as from one “edge”location to an opposing edge location of the membrane. In some cases,drive signal Iac may be an alternating current applied to one edge orlocation 126 of membrane 120 that flows through the membrane to thesecond or opposite edge or location 128 of membrane 120, as shown inFIG. 1B. In some cases, electronic contacts in the upper support, thevibrating membrane, or the lower support are electrically coupled toedges 126 and 128 of the vibrating membrane, for supplying or conductingan alternating current through the vibrating membrane.

In some embodiments, magnet 150 is a conductive or semi conductivematerial that is electronically isolated from membrane 120. In theseembodiments, magnet 150 is electronically isolated from conductivemember 130. That is, while signal Iac flows through membrane 120, itdoes not flow through magnet 150 or lid 110. Magnet 150 may beelectronically isolated from member 130 by using an isolative epoxy, anisolative adhesive, or an insulating layer between magnet 150 and member130.

It is considered that in some embodiments, lid 110 may be a conductiveor semi conductive material that is electronically isolated frommembrane 120. Here, lid 110 may be electronically isolated fromconductive member 140 by using an isolative epoxy, an isolativeadhesive, or an insulating layer between magnet 150 and member 140.

Membrane 120 may flex upwards or downwards, depending on whether thecurrent Iac flowing through the membrane as shown is from right to left,or from left to right). In some embodiments, the frequency of Iac ischosen or predetermined so that the membrane forms a single peak orvalley at its center C as it vibrates up and down at the frequency ofIac. This may be the “first vibrational mode” or “first harmonic” ofmembrane 120. In some cases, Iac is selected to have a frequency and anamount of current to cause the vibrating membrane 120 to vibrate withselected amplitude 127 as noted herein and at a selected frequency equalto the frequency of Iac. As the membrane vibrates, it pulls air throughopening 116 and into cavity 118 when it flexes downwards; and then itpushes air out of cavity 118 through opening 116 when it flexes upwards.The pushing out of air may be described as creating “puffs” (e.g.vortices) of air. The puffs may be created at the frequency of Iac. Itcan be appreciated that if opening 116 is exposed to or in an ambient ofliquid (e.g., fluid), device 100 (e.g., membrane 120) can create puffsof liquid. Although, opening 116 is shown centered in lid 110 (e.g., theopening has a central or bore axis aligned with center C), in some casesthe opening may be offset with respect to the center axis of membrane120. In some cases, opening 116 may be offset towards one of the edgesof the lid from the center by a distance of one tenth, one quarter, orone third of distance D1.

For instance, FIG. 1A, shows puffs 170 of air or liquid (1) exitingopening 116 and (2) entraining surrounding air or fluid EA. Puffs 170may exit opening 116 at a puff airflow velocity sufficient to entrainsurrounding air EA while membrane 120 vibrates up and down (e.g.,vibrates at the frequency of Iac). In some cases, air EA is air adjacentto or beside opening 116 that is pulled along with puffs 170 to form anet outwards (upwards and away from opening 116) flow of air at rate orvelocity R. In some cases, the combination of puffs 170 and entrainedair EA form a “jet” flow of air at velocity R that can be used forapplications noted herein.

In some cases, rate R will depend upon, the parameters: amount ofcurrent Iac, frequency of Iac, magnetic field strength, diameter D1,diameter D2, height of member 140, height of lid 110, and membrane 120thickness and material. Those parameters may be selected orpredetermined to maximize R.

In some cases, device 100 is designed so that the Helmholtz frequency ofcavity 118 matches the resonant frequency of membrane 120, thus causinga maximum of flow of air or fluid, or a maximum of rate R. For example,height H5, diameter D2 and/or the volume of cavity 118 are selected tothat the Helmholtz frequency of cavity 118 matches the resonatefrequency of membrane 120. In some cases, the thickness H1 or height ofmembrane 120, diameter D1, diameter D2, and volume of cavity 118 may beselected such that the Helmholtz frequency of cavity 118 is equal to theresonant frequency of membrane 120.

Although membrane 120 (and lid 110, supports 130 and 140, and magnet150) are shown having a circular shape from above (e.g., see FIG. 1B),other shapes are contemplated. For example, they may have the shape ofan oval, a square, a rectangle, a triangle, a rhombus, a trapezoid, or apolygon. It is considered that the cross sectional area of that shapewill be the same as described for the circular diameter (e.g., D1, D3 orP as applicable). In some cases, instead of a circular diameter (e.g.,D2), opening 116 may have an inner perimeter that has the shape of anoval, a rectangle, a square, a triangle, a rhombus, a trapezoid, or apolygon. In some cases, the cross sectional area of that shape will bethe same as described for the circular diameter (e.g., D2).

Some embodiments include a synthetic jet device (e.g., device 100, 301,401 or 501) formed within or as layers of a package substrate havinglayers of conductive traces, conductive vias, and dielectric material.Puffs of air expelled through an orifice of the device entrainsurrounding air and generate an air jet which may provide a controlledamount of airflow (e.g., rate R of FIG. 1) and/or a localized coolingairflow (e.g., see flow 216 of FIG. 2). In some cases, drive signal Iacto the jet device is provided from a source of alternating current, suchas a control circuit or a processor attached to a package substrate thatincludes the jet device.

In addition, although opening 116 is shown through lid 110, in someembodiments, opening 116 may be formed through another component of thejet. In some embodiments, opening 116 may be an opening as described foropening 116, except that it is an opening through a location of support140 (e.g., and there is no opening through lid 110). In this case, theopening may extend from a location in the inner perimeter of support 140directly outward (e.g., horizontally and having a center axis alignedwith a line extending outward from the center C of the jet) through thesupport and exiting the outer perimeter of the support. In this case, D2may be less than or equal to H4. Here, the puffs 170 and flow 216 mayexit the opening through support 140 in a horizontal (e.g., a lateral orradial) direction, such as to provide controlled flow or cooling in alateral or radial direction to the side of the jet. In some cases, thedescriptions herein for forming opening 116 apply to forming the openingthrough support 140. In some cases, the descriptions herein forpatterning and etching; forming openings through; or removing a portionof a conductor or metal can be used to form the opening through support140. In some cases, a jet having the opening through support 140 may bedisposed on its side so that the flow is directed upwards.

FIG. 2 shows an embodiment of a system including a synthetic jet deviceaccording to embodiments of the invention. FIG. 2 shows system 200including device 100. In some cases, the device 100 of FIG. 2 representsdevice 301, 401 or 501. Substrate 210 is shown having top surface 212and bottom surface 214. System 200 includes package substrate 210 havingdevice 100 disposed within or formed within substrate 210. In this case,surface 112 is part of a layer of substrate 210 formed below surface212, and surface 154 is part of a layer of substrate 210 formed abovesurface 214. Other cases contemplate that device 100 may have surface112 disposed flush within or formed flush within surface 212 ofsubstrate 210. In some cases, device 100 may have surface 154 disposedflush within or formed flush within surface 214 of substrate 210.

Substrate 210 is shown having top contacts 220, 222 and 224 formed on,in, or above surface 212. Substrate 210 is shown having bottom contacts226 and 228 formed on, in, or below surface 214. Substrate 210 is shownhaving electrical traces (e.g., conductive traces, wires, or the like)240, 241, 242, 243, 244, 245 and 246. Substrate 210 is shown havingconductive vias or interconnects 230, 231, 232, 234, 235 and 236. Via230 connects trace 240 to trace 241. Via 231 connects trance 241 tocontact 226. Via 232 connects trace 242 to trace 243. Via 234 connectstrace 244 to trace 245. Via 235 connects trace 245 to trace 246. Via 236connects trace 246 to contact 228.

Substrate 210 may be or include a packaging substrate having a pluralityof layers, the layers including layers of electronic traces, electronicvias and dielectric material. In some cases, substrate 210 is part of apackage substrate, such as a package substrate for packaging, orinterfacing to a microprocessor, computer processor “chip”, or otherlogic circuitry (e.g., having active devices (e.g., transistors) and/orresistors, capacitors and diodes) as known in art. Substrate 210 may bea package substrate for packaging or upon which a computer processor ismounted, such as to interface the processor with board 270, a“motherboard”, a printed circuit board, or another board having contactsand traces for interconnecting with processor 250 through substrate 210as known in the art.

Substrate 210 may have synthetic jet device 100 disposed or encasedcompletely within substrate 210, or within the layers of substrate 210.In some cases, device 100 is formed during formation of the layers ofsubstrate 210. For example, membrane 120, and support 140 may be formedas layers or during formation of layers of package substrate 210, suchas by processing known to form a packaging substrate. In some cases, lid110 is formed during formation of substrate 210. In some cases, lid 110is attached to device 100 during formation of substrate 210.

For example, membrane 120, support 130, or support 140 may be formedduring formation of trace 245. For example, membrane 120, support 130,or support 140 may be formed during formation of trace 245 duringformation of trace 243. Also, lid 110 may be formed during formation ofa dielectric layer above trace 245 or trace 243. In some cases, magnet150 may be attached to support 130, after dielectric is etched to removethe dielectric from between supports 130 to form cavity 114 (while notetching supports 130 or membrane 120).

In some cases, magnet 150 is formed during a separate process than theone for forming package substrate 210, and is attached to packagesubstrate 210 during formation of package substrate 210. In some cases,lid 110 is formed during a separate process than the one for formingpackage substrate 210, and is attached to package substrate 210 duringformation of package substrate 210. In some cases, both lid 110 andmagnet 150 are formed during a separate process than the one for formingpackage substrate 210, and are attached to package substrate 210 duringformation of package substrate 210. Attachment of magnet 150 and/or lid110 may include using an epoxy, adhesive, or other bonding process. Thisattachment may include electronically insulating magnet 150 from thelower support and/or lid 110 from the upper support, as noted above.

System 200 includes processor 250, which may be mounted on orelectrically coupled to surface 212. Processor 250 may be amicroprocessor, computer processor, chip, or other logic circuitry(e.g., having active devices (e.g., transistors) and/or resistors,capacitors and diodes) as known in art. Processor 250 has top surface252 and bottom surface 254. Processor 250 has contacts 260, 262 and 264.Processor 250 has data input/output (I/O) circuit 266 attached tocontact 260 by data line 268. Processor 250 has control circuit 256attached to contact 262 by control circuit line 257. Processor 250 hasground circuit 258 attached to contact 264 by ground line 259.

System 200 includes board 270 having top surface 272 and bottom surface274. Board 270 has contacts 280, 282 and 284. Ground circuit 286 isconnected through line 287 to contact 282. Board 270 includes trace 288connecting contact 280 to contact 284. Board 270 may be a “motherboard”,printed circuit board, or other board having contacts and traces forinterconnecting with processor 250 through substrate 210 as known in theart.

It can be appreciated that processor 250 may provide data input andoutput from circuit 266 through line 268, contacts, traces, and vias asshown to provide input/output (IO) data at contact 284. This 10 data mayrepresent data to/from a computer processor, memory, co-processor, bus,and the like as known in the art.

In some cases, control circuit 256 may provide control signals, such asalternating current Iac to membrane 120 through the following features:line 257, contacts 262 and 222, traces 242 and 243, and via 232. It canbe appreciated that board 270 may provide voltage bias or power (e.g.,Vcc, Vdd, and the like) to processor 250 through substrate 210, such asis known in the art. It can be appreciated that board 270 may providevoltage bias or power to substrate 210, such as is known in the art.

FIG. 2 also shows flow 216, such as a flow of air or liquid. Flow 216may represent the combination of puffs 170 and entrained air EA flowingat rate R as described for FIG. 1. Flow 216 is shown entering gap 218.Gap 218 may be a cavity, chamber, or opening in package 210 into whichit is desired to have flow 216 enter (e.g., selected or predeterminedlocations), such as for applications described herein. Such applicationsmay include providing a controlled flow rate R and/or a rate of flow Rfor cooling substrate 210 and/or processor 250. Gap 218 may be orinclude an air or liquid vent, pathway, tube, thin gap between orthrough layers of substrate 210. Thus, the mm-scale synthetic jetdevices herein can also provide airflow in very thin air gap (e.g., gap218) to increase cooling capacity (e.g., for a computer processor orprocessor package), where airflow has previously not been generated. Thepulsating flow from the synthetic jet devices provides a well suitedflow to break up thermal boundary layers (e.g., boundary 212) to createa more uniform temperature distribution. In some cases, the flow can bedirected to the cooling region, be impinged, directed at an angle,and/or parallel to the surface that requires cooling.

In some cases, flow 216 includes a flow of air at rate R for increasingcooling capacity where air flow was not previously generated (e.g., in,through or out of gap 218). In some cases, flow 216 includes a flow ofair at rate R for increasing cooling capacity where a forced air flowwas not previously generated to provide a well suited flow for breakingup thermal boundary layers to create more uniform temperaturedistribution in substrate 210; in or at processor 250; or for anotherdevice near or attached to substrate 210. In some cases the flow is tobreak up thermal boundary 212, such a thermal boundary under or at asurface of processor 250. Thermal boundary 212 may represent a boundarylayer resulting from processor 250 creating heat during use forcomputing performed by processor 250. Boundary 212 may represent aboundary where temperature increases moving away from substrate 210 andtowards processor 250. Boundary 212 may represent a boundary intemperature that it is desired to cool down or reduce using flow 216 orrate R. In some cases, a thermal boundary layer can be created and then“broken” up with a pulsating flow from the jet. In some cases, thesynthetic jet device can also increase cooling by impinging flow on asurface (perpendicular or at a different angle), parallel to the hotsurface and/or “bringing” cool air to a region where cooling is wanted.

FIGS. 3A-5 are examples of a package substrate formation process (e.g.,package technology) for forming synthetic jet devices such as thoserepresented by device 100 in FIGS. 1A, 1B and 2. The formation processesof FIGS. 3A-5 may include standard package substrate formation processesand tools such as those that include or use: lamination of dielectriclayers such as Ajinomoto build up films (ABF), laser or mechanicaldrilling to form vias in the dielectric films, lamination andphotolithographic patterning of dry film resist (DFR), plating ofconductive traces (CT) such as Copper (Cu) traces, and other build-uplayer and surface finish processes to form layers of electronicconductive traces, electronic conductive vias and dielectric material onone or both surfaces (e.g., top and bottom surfaces) of a substratepanel or peelable core panel. The substrate may be a substrate used inan electronic device package or a microprocessor package.

For example, FIGS. 3A-3H shows one example of a package substrateformation process for forming a synthetic jet device. FIGS. 3A-3H mayshow a process that can be used to create a synthetic jet device in apackage substrate with a die-side orifice (e.g., jet device opening 116)and a solder resist lid formed as part of the jet device (e.g., such aslid 110).

FIG. 3A shows peelable core 302 having a top and bottom surface uponwhich a layer of removable adhesive 304 may be formed. In some case, athin electroless “seed” layer of conductor such as copper (or nickel orgold) is formed on or over the adhesive. Core 302, adhesive 304 and theseed layer may be part of a pre-manufactured package substrate core asknown in the art of computer processor package device formation. Core302 may be formed of ajinomoto build-up film (ABF), glass-reinforcedepoxy laminate sheets (e.g., flame retardant-FR4), printed circuit board(PCB) sheets, an organic dielectric, metal or copper sheets or layers,or another material as known for creating a carrier board for a packagesubstrate.

A layer or islands 322 of conductor 320 may be formed on adhesive 304(or on the seed layer), such as by dry film resist (DFR) patterning andconductive plating. The plating may be electrolytic plating of conductor320 in the seed layer, between islands of DFR formed on adhesive 304 (oron the seed layer), as known in the art. Conductor 320 may be a metal.In some cases, conductor 320 is copper, nickel or gold. In some cases,conductor 320 is copper.

Then, a layer of insulator 310 may be formed on adhesive 304 (or on theseed layer). Insulator 310 may be a dielectric material as known in theart, such as a layer of ajinomoto build-up film (ABF). Insulator 310 maybe formed by an ABF lamination process as known in the art.

Then, openings may be formed at selected or predetermined locations ininsulator 310 such as by using a laser as known in the art, such as acarbon dioxide laser, or by using a mechanical drill. Next, conductor(such as copper, or nickel, or gold) may be electroplated into theopenings to form vias such as supports 130 and vias 324, and overselected or predetermined portions of insulator 310 to form traces 326and membrane 120. For example, traces 326 and membrane 120 of conductor320 may be formed by DFR photolithographic patterning and conductivemetal plating (e.g., copper plating). In some cases, they are formedupon an electroless seed layer of conductor or metal formed on insulator310 upon which the conductor may be plated.

In some cases, traces 326 are formed upon vias 324 and membrane 120 isformed on support vias 130 and over insulator 310 between support vias130. In some cases, conductor 320 forms support 130, conductive vias324, traces 326 and vibrating membrane 120.

In some cases, insulator 310 may have a thickness of between 15 and 35micrometers. In some cases the thickness may be 25 micrometers. Thethickness of insulator 310 may be equal to the height of cavity 114,such as by being height H2. Membrane 120 may have height H1, such thatthe top surface of membrane 120 is height H1+H2 above removable adhesive304. Similarly, trace 326 may have a top surface at height H1+H2 aboveadhesive 304.

FIGS. 3A-3G show a substrate package formation process that starts witha first jet device 301 being formed on the top side of core 302 and asecond, mirror image jet device 303 formed on the bottom surface of core302. For example, line L-L′ divides the core across its center so thatbelow line L-L′ is a mirror image of what is above line L-L′. It can beappreciated that by using such packaging substrate formation technologyor processes two jet devices are being formed at once, thus forming themat twice the rate of formation as compared to using a single-sidepolished silicon, wafer, or chip forming process. For example, thepackaging processes described for FIGS. 3A-3E, form most of two jetdevices at once (e.g., during or using the same processing process) on asingle package substrate. The remaining packaging processes describedfor FIGS. 3F-3H, to form the rest of the two jet devices may beperformed at once (e.g., during or using the same processing process) orat different times on the separated substrates or devices 301 and 303.

FIG. 3B shows the substrate of FIG. 3A after laminating a second layerof insulator on the substrate. Layer of insulator 330 may be laminatedon surfaces of insulator 310, conductor 326 and membrane 120. Thislamination may be similar to that described for layer 310. Next, laserholes are drilled in insulator 330. These holes may be formed asdescribed for holes formed in layer 310. Then, the holes may be platedwith conductor to form vias 340. Plating may be done as described forplating to form vias 324.

Next, a layer of conductive material may be formed on vias 340 andsurfaces of insulator 330. Forming the layer of conductive material maybe similar to descriptions for forming layer 326 and 120. This layer maybe described as mesh layer 344 which includes islands 342 on vias 340;islands 348 over layer 330 over membrane 120 (e.g., between support130); and thin layers of conductor 346 between islands 342 and islands348. Thus, conductor 320 may be formed on surfaces of layer 330 to formvias, traces and mesh layer 344. In FIG. 3B there may be a thin layer ofconductive material 346 in layer 344 formed over the entire top surfaceof insulator layer 330 used as a seed layer for mesh layer 344. Thisthin layer is identified as layer 346 between the thicker parts 342 and348 of the mesh.

FIG. 3C shows the substrate of FIG. 3B after patterning of thin layer346 to form a hard mask for etching the upper cavity (e.g., cavity 118)of the jet device. FIG. 3C shows substrate 300 after patterning of layer346 (e.g., using DFR lamination, lithography to pattern the DFR, and awet etch process to pattern layer 346) to create a hard mask for etchingthe upper cavity (e.g., cavity 118) of the jet. FIG. 3C shows patterningto expose openings 350 to the top surface of insulator layer 330 betweenmesh islands 348. Openings 350 are where layer 346 was removed betweenislands 342 and 348, and in between islands 348, over layer 330 overmembrane 120 (e.g., between supports 130). This wet etch used to patternlayer 346 may be selective to remove conductive material 320 but notinsulator material 310.

Lamination of DFR on top of layer 346 and patterning it usinglithography may protect thin layer 346 at locations 352 which areadjacent to and outside diameter D4 of what will be the top cavity ofthe jet device. In some cases, the etch of layer 346 in mesh layer 344may comprise a wet etch for a selected or predetermined amount of timeto remove thin layer 346 where it is exposed to the etchant (e.g., whilelocations 352 are protected or masked by DFR) but not remove all of thethickness of, or remove only a selected or predetermined thickness ofislands 348. Locations 352 may be used to protect portions of insulator330 that may not be part of the jet device from the subsequent insulatoretching process used to create the cavity (e.g., cavity 118) of the jetdevice.

FIG. 3D shows the substrate of FIG. 3C after etching away a portion ofinsulator layer 330 above membrane 120 to form top cavity 318. In somecases cavity 318 represents cavity 118 of FIG. 1. In some cases, vias340 and islands 342 represent support 140 as described for FIG. 1. Insome cases, islands 342, vias 340, islands 326, vias 324, and islands322 represent support 140 as described for FIG. 1. This etch may beselective to remove insulator material 310 but not conductive material320.

Etch 360 may be an etch through openings 350 between islands 348 ofconductor to remove layer 330 from cavity 318, but not to remove layer330 outward of islands 348, such as where layer 330 is protected atlocations 352 by thin layer 346 of mesh 344. In some cases, etch 360 maybe an isotropic etch. The etch may remove layer 330 of insulator but notlayer 310 such as by being an etch for a selected or predeterminedamount of time to remove layer 330 from cavity 318 but not for longenough to remove layer 310 of insulator. In some cases, etch 360 is aplasma etch of carbon tetrafluoromethane (CF4), sulphur hexafluoride(SF6), nitrogen trifluoride (NF3), or another known etchant or etch toremove material of layer 330 (e.g., to remove insulating material orABF).

FIG. 3E shows the package substrate of FIG. 3D after removing theremainder of the thin layer 346, such as by using a wet etch, followedby forming a layer of solder resist material 370; and solder resistpatterning of the layer to form lid 110 and opening 116 of the jetdevices. FIG. 3E shows solder resist 370 such as an insulating organicmaterial, laminated material, photosensitive material, or other knownsolder resist material. Solder resists 370 may be an insulator materialformed during a substrate package formation process as described herein.Solder resist 370 may include openings 372 and 116 formed through resist370 by patterning and developing as known in the art. This developingprocess may be selective to remove resist 370 in designated locations(e.g., openings 116 and 372) which were exposed or masked from exposureto light via a lithography process, depending on whether a positive ornegative tone resist is used, while keeping layer 370 intact in theremaining locations. Furthermore the developing process may be chosen tobe selective so as not to remove insulator material 310 or not conductor320. Resist 370 may have height H5 that may be between 5 and 50micrometers.

FIG. 3E shows substrate 300 having top jet device 301 and bottom, secondjet device 303. It can be appreciated that as described for FIG. 3A, forFIGS. 3A-3E, two jet devices are being formed at once (e.g., during orusing the same or subsequent processing process) on a single packagesubstrate.

FIG. 3F shows the substrate from FIG. 3E after de-paneling devices 301and 303; flipping device 301; patterning and forming a hard mask (e.g.,using a thin layer of conductor or copper, not shown) on the exposedsurface of layer 310 (top surface in FIG. 3F) outside the area withinwhere bottom cavity 114 will exist; ABF etching to remove layer 310 toform cavity 114; and finally removing the hard mask from the surface oflayer 310 (e.g., by using a wet etch process). During this entireprocess sequence, the solder resist layer 370 may be protected fromundesired etching by coating it with a passivation layer, such assilicon nitride (SiN), before any etching is started, and eventuallyremoving this passivation layer at the end of the process flow sequencedescribed above. In some cases, FIG. 3F shows the substrate from FIG. 3Eafter separating devices 301 and 303; and etching to remove a portion oflayer 310 between supports 130. FIG. 3F shows jet device 301 afterremoving peelable core 302 and removable adhesive 304 from bottomsurfaces of insulator 310, conductor 322, and support 130. Thisseparation process may include first forming a protective passivationlayer (e.g., SiN, not shown) on top surfaces of layer 370, which will beremoved after etching to remove layer 310 to form cavity 114. Removal ofthe core 302 and adhesive 304 may be done during a package formationprocess, as known in the art.

It can be appreciated that the processes described for device 301 inFIGS. 3F-G can also be performed on device 303 to create a second jetdevice from the substrate of FIG. 3E.

The bottom of device 301 (top surface in FIG. 3F) may then be coveredwith a hard mask (e.g., a thin electroless layer of conductor or copper,not shown) which may be formed over the exposed surface of layer 310outside the area within where cavity 114 will exist to protect layer 310outside of or away from bottom cavity 114 during etch 374 (e.g., outsideof diameter D1).

Next, etch 374 may remove all of insulator 310 between support 130, orwithin diameter D1 (see also FIG. 1), but not remove layer 310 outsideof where support 130 exists due to protection of that part of layer 310by the hard mask (e.g., a thin electroless layer of conductor or copper,not shown). Etch 374 may be a plasma etch to remove ABF material, suchas to remove layer 310 to form cavity 114. Etch 374 may be an etch oruse an etchant similar to etch 360. This etch may be selective to removeinsulator material 310 but not remove conductor 320.

After etch 374, any remaining hard mask (e.g., a thin electroless layerof conductor or copper, not shown) outside of supports 130 (e.g.,outside of diameter D1) may be removed or etched away to exposeinsulator 310 as shown in FIG. 3F. Removing the electroless hard maskmay include wet etching of the electroless hard mask from the top oflayer 310 in FIG. 3F that was above the surface of and protecting theremaining layer 310. After that hard mask etch, another wet or dry etchmay be performed to remove the protective passivation layer (e.g., SiN)that was formed over lid 110 to protect the lid during the process flowsequence used to form cavity 114.

FIG. 3G shows the substrate of FIG. 3F after attaching or forming magnet150 to or over surfaces of support 130. FIG. 3G shows device 301 havingmagnet 150 attached to or over surfaces of support 130. In some cases,this attachment is as described for FIG. 1A-B.

In FIG. 3G, a magnet (e.g. magnet 150) may be attached on the board sideof the package substrate. This is possible because the magnet thickness(e.g., height H3) can be selected or predetermined to be smaller or lessthan the post-collapse height of the ball grid array (BGA). That is, theheight of the magnet may be less than the height of solder balls used ina BGA that will surface mount the package substrate (e.g., substrate210) onto a board (e.g. board 270). In some cases, the height of themagnet (e.g., H3 of magnet 150) may be 200 micrometers, or between 100and 300 micrometers. Such magnets may be assembled to a packagesubstrate (e.g., substrate 210 or device 301) using a pick and placeprecision assembly tool or a chip cap shooter tool of a packagesubstrate formation process. In some cases the magnet can be attached byusing an epoxy or adhesive applied to the magnet and/or the surface ofsupport 130. In some cases the cap shooter is a device where the magnet,having metalized edges, is shot onto a surface of the substrate and asolder reflow process is performed to cause the solder to attach themagnet to the substrate (e.g., support 130). The solder may be attachedto (dummy) bumps that are not electrically connected to support 130 sothat the magnet is electrically isolated from support 130 or membrane120.

FIG. 3G shows jet device 301 having lid 110 with opening 116 havingdiameter D2; top cavity 318 having diameter D4; bottom cavity 114 havingdiameter D1; lower support 130, upper support 340; and vibratingmembrane 120 attached to and formed on lower support 130. In some cases,the upper support may include vias 324 and 340 an islands 326. In somecases, the upper support may also include islands 342 and 348.

It can be appreciated that device 301 of FIG. 3G does not look exactlythe same as device 100 shown in FIG. 1. In some cases, in device 301,lid 110 may be formed on the upper support (e.g., islands 342 and 348)which are not formed on or touching membrane 120, such as shown forsupport 140 of device 100 of FIG. 1. Instead, in device 301, lid 110 maybe formed on the upper support such as by being formed over vias 324, atdifferent locations than where support 130 and membrane 120 were formedon core 302. However, it can be appreciated that the concepts describedabove with respect to device 100 apply as well to corresponding parts ofdevice 301. Moreover, descriptions above for cavity 118 may apply tocavity 318. Also, descriptions above for support 140 may apply tosupport 340. In some cases, descriptions above for selections orpredeterminations, such as of diameter, height and volume of cavity 118and support 140 may also be used for or apply to cavity 318 and support340. However, the concepts described for device 100 and flow rate R,etc. can be selected or predetermined based on cavity 318 and support340 substituting for cavity 118 and support 140.

FIG. 3H shows the device of FIG. 3G after forming solder bumps inopenings 372 adjacent to lid 110 through resist 370. Bumps 375 may beformed of various conductors such as tin, gold, nickel, and variousother materials known for forming solder bumps. Bumps 375 may be part offlip chip bump array. Bumps 375 may be die-side 376 of device 301 andmay be used to attach device 301 or a substrate containing device 301(e.g. substrate 210) to a processor (e.g., such as processor 250). Insome cases, bumps 375 represents contacts 224 and/or as shown in FIG. 2.FIG. 3H also shows board side 378 of device 301 as a side of the deviceupon which or towards which a board is attached (e.g. board 270). Insome instance, board side 378 is touching or attached to a board, suchas through contacts (e.g., contacts 228 and/or 226). In other instances,device 301 is located within a substrate, such as shown for device 100located within substrate 210 in FIG. 2. In some cases, bumps 375 may ormay not exist.

FIGS. 4A-4E show a second example of a package substrate formationprocess for forming a synthetic jet device. FIGS. 4A-4E show a secondexample that continues from or using the substrate of FIG. 3A. FIGS.4A-4E may show a process that can be used to create a synthetic jetdevice in a package substrate with a die-side orifice formed in adiscrete lid assembled (e.g., jet device opening 416 formed in discretelid 410 which is separately attached to the jet device as opposed tobeing formed on it or laminated on it) as part of the jet device.

As compared to FIGS. 3B-3G, in FIGS. 4A-4E the opening through the lidis now in a discrete lid assembled on the die side, and the islands 348and thin layers 346 of mesh 344 are eliminated and replaced with an open“window” 450 and the top cavity 418 may be created after the solderresist lamination 449 takes place. This can be advantageous if thesolder resist lamination 370 on top of the mesh 344 in FIGS. 3E-3H isfound to cause significant mesh 344 deformation. Moreover, by replacingthe mesh in FIGS. 3E-3H with an open window 450, the etching 460 of FIG.4B of the underlying ABF layer 330 from within upper support 340 isexpected to occur at a faster rate than the etching 360 of FIG. 3D.

FIGS. 4A-4B show a substrate package formation process where a first jetdevice 401 may be formed on the top side of core 302 and a second,mirror image jet device 403 may be formed on the bottom surface of core302 of substrate 300. This may provide advantages similar to those notedfor FIGS. 3A-3G where jet devices 301 and 303 are formed on top andbottom sides of core 302, such as using such packaging substrateformation technology or processes during which two jet devices are beingformed at once, thus forming them at twice the rate of formation ascompared to using a single side polished silicon, wafer, or chip formingprocess. For example the packaging processes described for FIGS. 4A-4B,form most of two jet devices at once (e.g., during or using the same orsubsequent processing process) on a single package substrate. Theremaining packaging processes described for FIGS. 4C-4E, to form therest of the two jet devices may be performed at once (e.g., during orusing the same or subsequent processing process) or at different timeson the separated substrates or devices 401 and 403.

FIG. 4A shows the substrate of FIG. 3A after deposition and patterningto create a hard mask for etching to form top cavity 418. FIG. 4A mayshows the substrate of FIG. 3A after depositing a thin hard mask layer(such as an electrolessly plated conductor or metal, e.g. copper) andpatterning it using DFR to create a hard mask for etching to form topcavity 418. FIG. 4A may show the substrate of FIG. 3A after laminating asecond layer of insulator 330 on the substrate 300, drilling holes inlayer 330 and plating the holes with conductor to form vias 340, such asis described for FIG. 3B.

Next, a layer of conductive material may be formed on vias 340 andsurfaces of insulator 330 to form islands 342. Forming the layer ofconductive material may be similar to descriptions for forming layer 342in FIG. 3B except that the islands 348 and thin layers 346 of mesh 344are eliminated and replaced with an open “window” 450.

Next, layer of solder resist 449 may be formed on the layer ofconductive material that may be formed on vias 340. Resist 449 may be amaterial that is formed during a substrate package formation process asdescribed for solder resist 370. Solder resist 449 may include openings472 and 450 formed through resist 449 by patterning and developing asdescribed for layer 370 and/or as known in the art. The patterning anddeveloping may include patterning of a photosensitive solder resist toopen up locations where lid 410 or solder bumps 375 that are used fordie attach are to be added later. Resist 449 may have height that ispart of H4.

Then a thin hard mask layer 446 may be formed over the remaining partsof layer 449 (and optionally islands 342 in openings 472) such as byelectroless plating; or by plating and then etching the thin layer fromopening 450. This mask 446 may be a thin layer of conductor 320 (e.g., athin layer of copper) formed by electroless deposition and patterningusing DFR to create a hard mask for etching through or of opening 450 toremove layer 330 below opening 450 to form top cavity 418.

FIG. 4B shows the substrate of FIG. 4A after etching away a portion ofinsulator layer 330 above membrane 120 to form top cavity 418. In somecases cavity 418 represents cavity 118 of FIGS. 1A-B. In some cases,vias 340 and islands 342 represent support 140 as described for FIGS.1A-B. In some cases, islands 342, vias 340, islands 326, vias 324, andislands 322 represent support 140 as described for FIGS. 1A-B.

Etch 460 may be an etch through opening 450 between islands 342 ofconductor to remove layer 330 from cavity 418, but not to remove layer330 outward of inner side surfaces 448 of islands 342, such as wherelayer 330 is protected by islands 448. In some cases etch 460 may be anetch for a selected or predetermined amount of time. In some cases, etch460 may be an anisotropic etch. This etch may be selective to removeinsulator material 330 but not conductor 320. In some cases, etch 460uses an etch chemistry described for etch 360. Mask 446 may be removedafter etching of layer 330 by using a wet etch process as described forremoving thin layer 346.

Creating top cavity 418 after the solder resist lamination 449 takesplace can be advantageous if the solder resist lamination 370 on top ofthe mesh 344 in FIGS. 3E-3H is found to cause significant mesh 344deformation. Moreover, by replacing the mesh in FIGS. 3E-3H with an openwindow 450, the etching 460 of FIG. 4B of the underlying ABF layer 330from within upper support 440 is expected to occur at a faster rate thanthe etching 360 of FIG. 3D.

FIG. 4C shows the substrate of FIG. 4B after passivating the exposedsurface of the solder resist layer 449 (for example, by depositing athin layer 452 of SiN over that surface); de-paneling devices 401 and403; flipping device 401, patterning and forming a hard mask 462 (e.g.,a thin layer of electrolessly plated conductor or copper) on the bottomof device 401 (top side in FIG. 4C) outside the area within where cavity114 will exist. In some cases, FIG. 4C shows the substrate from FIG. 4Bafter separating devices 401 and 403. FIG. 4C shows jet device 401 afterremoving peelable core 302 and removable adhesive 304 from bottomsurfaces of insulator 310, conductor 322, and support 130 such asdescribed for FIG. 3F.

It can be appreciated that the processes described for device 401 inFIGS. 4C-F can also be performed on device 403 to create a second jetdevice from the substrate of FIG. 4B.

The bottom of device 401 (top side in FIG. 4C) may then be patterned andan electroless hard mask 462 may be formed over the exposed surface oflayer 310 outside the area within where cavity 114 will exist to protectlayer 310 outside of or away from bottom cavity 114 during etch 474(e.g., outside of diameter D1).

FIG. 4D shows the substrate from FIG. 4C after etching to remove aportion of layer 310 between supports 130. FIG. 4D may include ABFetching to remove layer 310 to form cavity 114; removal of theelectroless hard mask 462 (e.g., a thin layer of conductor or copper) bya wet etch process for example; and final etching process to remove thepassivation layer 452 from surfaces of device 401.

Etch 474 may remove all of insulator 310 between support 130, or withindiameter D1 (see also FIGS. 1A-B), but not remove layer 310 outside ofwhere support 130 exists due to protection of that part of layer 310 bythe electroless hard mask 462. Etch 474 may be an ABF etching to removelayer 310 to form cavity 114. This etch may be selective to removeinsulator material 310 but not conductor 320. Etch 474 may be an etch oruse an etchant similar to etch 360.

After etch 474, any remaining electroless hard mask 462 outside ofsupports 130 (e.g., outside of diameter D1) may be removed to exposeinsulator 310 as shown in FIG. 4D. Removing the electroless hard maskmay include a wet etch of the electroless hard mask to remove it fromthe surface of device 401. After that etch, another etching process(e.g., an etch that attacks SiN) may be performed to remove passivationlayer 452 that was formed on surfaces of device 401.

FIG. 4E shows the substrate of FIG. 4D after attaching magnet 150 to orover surfaces of support 130, forming solder bumps in openings 472 oflayer 449 and attaching lid 410 to surfaces of layer 449. FIG. 4E showsdevice 401 having magnet 150 attached to or over surfaces of support130.

In FIG. 4E, a magnet (e.g. magnet 150) may be attached on the board sideof the package substrate. This may be similar to mounting magnet 150 inFIG. 3G. After attaching magnet 150 solder bumps 375 may be formed inopenings 472 adjacent to lid 410 through resist 449. Bumps 375 may be ofa similar material and attached to a similar die or processor asdescribed for bumps 375 of FIG. 3H.

In FIG. 4E, lid 410 may be attached on the die side of the packagesubstrate. This may be done before or after forming bumps 375. In somecases, the height of the lid (e.g., H5) may be 200 micrometers, orbetween 100 and 500 micrometers. Such attachment may include assemblingthe lid to a package substrate (e.g., substrate 210 or device 401) usinga pick and place precision assembly tool or a chip cap shooter tool of apackage substrate formation process. In some cases the lid can beattached by using an epoxy or adhesive applied to the lid and/or thesurface of the substrate (e.g., surface of layer 449). In some cases thecap shooter is a device where the lid, having metalized edges, is shotonto a surface of the substrate and a solder reflow process is performedto cause the solder to attach the lid to the substrate (e.g., layer449). The solder may be attached to (dummy) bumps that are notelectrically connected to membrane 120 so that the lid is electricallyisolated from membrane 120.

FIG. 4E shows jet device 401 having lid 410 with opening 416 havingdiameter D2; top cavity 418 having diameter D41; bottom cavity 114having diameter D1; lower support 130, upper support 340; and vibratingmembrane 120 attached to and formed on lower support 130. In some cases,the upper support may include vias 324 and 340, and islands 326 and 342,and layer 449. In some cases, the upper support may include layer 330,and island 342, and layer 449 such as to be an upper support attached tothe top surface of membrane 120.

It can be appreciated that device 401 of FIG. 4E does not look exactlythe same as device 100 shown in FIGS. 1A-B. In some cases, in device401, lid 410 may be formed on the upper support (e.g., layer 449) whichare not formed on or touching membrane 120 such as shown for support 140of device 100 of FIGS. 1A-B. Instead, in device 401, lid 410 may beformed over layer 449 and vias 324 which were formed, at differentlocations than where support 130 and membrane 120 were formed on core302. However, it can be appreciated that the concepts described abovewith respect to device 100 apply as well to corresponding parts ofdevice 401. Moreover, descriptions above for cavity 118 may apply tocavity 418. Also, descriptions above for support 140 may apply tosupport 340. In some cases, descriptions above for selections orpredeterminations, such as of diameter and height of cavity 118 andsupport 140 may also be used for or apply to cavity 418 and support 340.The concepts described for device 100 and rate R, etc. can be selectedor predetermined based on cavity 418 and support 340 substituting forcavity 118 and support 140.

As compared to FIGS. 3B-3G, in FIGS. 4A-4E the opening through the lidmay be now through a discrete lid assembled or attached on the die sideof device 401.

FIG. 5 shows a third example of a package substrate formation processfor forming a synthetic jet device. FIG. 5 shows a third example thatcontinues from or using the substrate of FIG. 4D. FIG. 5 may show aprocess that can be used to create a synthetic jet device in a packagesubstrate with a board-side 378 orifice formed in a discrete lidassembled (e.g., jet device opening 516 formed in discrete lid 510) aspart of the jet device.

As compared to FIGS. 4A-4E, in FIG. 5 the opening through the lid may benow in a discrete lid assembled on the board side 378 and the magnet maybe on the die side 376 of the package substrate. Attaching a discretelid can be advantageous as described for FIGS. 4A-4E as compared toFIGS. 3E-3H. In this configuration, the lid thickness H5 must be chosento be less than the height of the BGA balls (not shown) used to attachthe package substrate (e.g., substrate 210) to the board (e.g., board270). Also, a hole may be needed in the board (e.g., board 270) to allowair exchange with the environment through the orifice (e.g., opening516).

FIG. 5 shows the jet device of FIG. 4D after attaching lid 510 tosurfaces of support 130, forming solder bumps in openings of layer 449and attaching magnet 550 to or over surfaces of layer 449. As comparedto FIG. 4E, in FIG. 5, the sides of device 401 (e.g., sides 376 and 378)that the magnet and lid are attached to may be reversed.

FIG. 5 shows device 501 having lid 510 attached to or over surfaces ofsupport 130 on board side 378. Lid 510 may be the same material andthickness (and formed the same way) as lid 410, but may have an openingdiameter D2 size designed for cavity 114. Lid 510 may be attached tosurfaces of support 130 as described for attaching lid 410 to layer 449in FIG. 4E. In this case, cavity 114 of FIG. 1 is now cavity 414 in FIG.5 and selections and predeterminations for that cavity (e.g., see cavity114 in FIG. 1) apply to cavity 414 of FIG. 5.

In FIG. 5, magnet 550 is attached on the die side 376 of the packagesubstrate. Magnet 550 of FIG. 5 may be the same material and thickness(and formed the same way) as magnet 150 of FIG. 4, but may have adiameter size designed for cavity 414. Magnet 550 may be attached tosurfaces of layer 449 as described for attaching magnet 150 on support130 in FIG. 3G. In this case, cavity 118 in FIG. 1 is now cavity 418 inFIG. 5 and selections and predeterminations for that cavity (e.g., seecavity 118 in FIG. 1) apply to cavity 418 of FIG. 5. Solder bumps 375may be formed in openings 372 adjacent to magnet 550 through resist 449.Bumps 375 may be of a similar material and attached to a similar die orprocessor as described for bumps 375 of FIG. 3H.

In FIG. 5, a magnet (e.g. magnet 550) may be attached on the die side376 of the package substrate. In some cases, the height of the magnet(e.g., H3 of magnet 550) may be 200 micrometers, or between 100 and 500micrometers. Such magnets may be assembled to a package substrate (e.g.,substrate 210 or 300) using a pick and place precision assembly tool ora chip cap shooter tool of a package substrate formation process. Insome cases the magnet can be attached by using an epoxy or adhesiveapplied to the magnet and/or the surface of the substrate (e.g., layer449). In some cases the cap shooter is a device where the magnet, havingmetalized edges, is shot onto a surface of the substrate and a solderreflow process is performed to cause the solder to attach the magnet tothe substrate (e.g., layer 449). The solder may be attached to (dummy)bumps that are not electrically connected to support 130 so that themagnet is electrically isolated from support 130 or membrane 120.

In FIG. 5, lid 510 may be attached on the board side 378 of the packagesubstrate. This is possible because the lid thickness (e.g., height H5)can be selected or predetermined to be smaller or less than thepost-collapse height of the ball grid array (BGA). That is, the heightof the magnet may be less than the height of solder balls used in a BGAthat will surface mount the package substrate (e.g., substrate 210) ontoa board (e.g. board 270). In some cases, the height of the lid (e.g.,H5) may be 200 micrometers, or between 100 and 300 micrometers. Suchattachment may include assembling the lid to a package substrate (e.g.,device 501 or support 130) using a pick and place precision assemblytool or a chip cap shooter tool of a package substrate formationprocess. In some cases the lid can be attached by using an epoxy oradhesive applied to the lid and/or the support 130. In some cases thecap shooter is a device where the lid, having metalized edges, is shotonto a surface of the substrate and a solder reflow process is performedto cause the solder to attach the lid to the substrate (e.g., support130). The solder may be attached to (dummy) bumps that are notelectrically connected to membrane 120 so that the lid is electricallyisolated from membrane 120.

FIG. 5 shows jet device 501 having lid 510 with opening 516 havingdiameter D2. FIG. 5 shows a reversal of the position of the cavities andsupports as compared to FIG. 4E. It can be appreciated that device 501of FIG. 5 does not look exactly the same as device 100 shown in FIGS.1A-B. However, it can be appreciated that the concepts described abovewith respect to device 100 apply as well to corresponding parts ofdevice 501.

Moreover, descriptions of FIGS . 1A-B for cavity 118 may apply to cavity418 of FIG. 5. In some cases, the concepts of FIGS. 1A-B described fordevice 100 and rate R, etc. can be selected or predetermined based oncavity 418 of FIG. 5 substituting for cavity 118 of FIGS. 1A-B. Also,descriptions of FIGS. 1A-B for cavity 114 may apply to cavity 414 ofFIG. 5.

As compared to FIGS. 3B-3G, in FIG. 5 the opening through the lid may benow in a discrete lid assembled on the board side, and the magnet may bea discrete magnet assembled on the die side. As compared to FIGS. 4A-4E,in FIG. 5 the lid is now assembled on the board side, and the magnet isa discrete magnet assembled on the die side.

Embodiments described herein provide several advantages compared to theknown solutions such as the following. In some cases, the airflow fromembodiments of a synthetic jet device as described herein (e.g., device100, 301, 401 or 501) can be used to generate a controlled amount ofairflow (e.g., puffs 170, rate R, or flow rate of flow 216), such as forenvironmental monitoring and thermal management applications. Generatinga controlled amount of airflow may be a requirement in environmentalsensing applications in order to detect accurate concentrations ofparticles, pollutants, and/or toxic gases in a given environment.Generating a controlled amount of airflow may be a requirement to beable to deliver accurate concentrations for small scale and accuratesolutions for sensing and detection of concentrations for air qualityand mixtures. This functionality is in high demand for new devices suchas wearables (e.g., lab jackets, bracelets, watches), smartphones,tablets, etc. as well as Internet of Things (IoT) systems (e.g.,wireless office, retail, or industrial systems).

In some cases, the airflow from embodiments of a synthetic jet device asdescribed herein (e.g., device 100, 301, 401 or 501) can be used tocreate a sufficient amount of localized airflow (e.g., puffs 170, rateR, or flow rate of flow 216) for the thermal management or cooling ofprocessor packages (e.g., substrate 210 and/or processor 250). Asufficient amount of air flow can be used to enhance device and/or spotcooling in devices where active thermal management is generally not used(such as smartphones and tablets). It can be especially advantageouswhen placed close to the hot electronic components. Even a small airflow(e.g., flow 216) can be beneficial to reduce hot spot temperatures andto generate a more even temperature distribution in a processor package(or other hot component). By implementing the synthetic jet device onthe package close to the hot components (i.e., a processor 250 mountedon or in the package 210), the pulsating airflow generated 216 can beused to break-up a thermal boundary layer in the gap 218 and to enhancethe cooling capacity of the processor 250, allowing for higher powerprocessor workloads of the processor. According to some embodiments, jetdevice 100 shown in FIG. 2 may have opening 116 to or at surface 212 ofsubstrate 210. In this case, gap 218 does not exist, but instead flow216 flows directly from surface 212, such as where surface 112 of FIG.1A is level with (e.g., parallel to) or is the same surface as surface212. In some cases, this embodiment may provide better or increasedcooling of processor 250 (e.g., surface 254) as compared to those havinggap 218.

In addition, it is noted that embodiments herein describe using jetdevice 100 in substrate 210 to provide puffs 170 and flow 216 that exitan opening in a vertical and upwards direction with respect to a topsurface of substrate 210. However it is also considered that jet device100 may be disposed to have diameter D1 oriented vertically (e.g., bylocating device 100 to be on its side) in substrate 210 to provide puffs170 and flow 216 that exit an opening in a horizontal (e.g., a lateralor radial) direction with respect to a top surface of substrate 210.This may provide a controlled flow or cooling flow of air in apredetermined horizontal direction or to a predetermined location to theside of the jet (e.g., to cool a component to the side of the jetdevice). This may cool a component of or in substrate 210. In addition,in some cases, jet device 100 may be disposed to have diameter D1oriented upside down (e.g., by locating device 100 to be flipped 180degrees with respect to the direction of flow 216) in substrate 210 toprovide puffs 170 and flow 216 that exit an opening in a vertical anddownwards direction with respect to a bottom surface of substrate 210.This may provide a controlled flow or cooling flow of air in apredetermined vertical and downwards direction or to a predeterminedlocation below the jet (e.g., to cool a component below the jet device).This may cool a component of or on board 270.

Embodiments described herein provide several advantages due to usingpackaging formation processes instead of silicon chip or waferprocessing such as the following. In some cases, embodiments of asynthetic jet device as described herein (e.g., device 100, 301, 401 or501) are included in the creation of package-integrated synthetic jetdevices to generate airflow for these types of applications (e.g., seeFIGS. 2-5). Some cases include a process (e.g., see FIGS. 3A-5) forcreating synthetic jet devices directly in a package substrate. Some ofthe process flow may use standard substrate fabrication technology andan additional dielectric etch process to release the vibrating membrane(e.g., see FIGS. 3D and 3F; or FIGS. 4B and 4D). As the membranevibrates, “puffs” 170 of air are expelled through the orifice 116. Thesepuffs entrain surrounding air EA and generate an air jet 216 which mayprovide a controlled amount of airflow and/or a localized coolingairflow 216 or rate R.

Because some embodiments of the jet are manufactured with panel-levelpackage forming processes, it can be more cost effective than waferlevel processing (e.g., using silicon or other wafers). In addition,using package forming processes creates a jet that is easily integratedas part of and with the other layers of a package substrate (e.g., seeFIGS. 2-5). This integration also allows the jet driving signal (e.g.,current Iac) to be provided or driven by circuitry of a chip orprocessor (e.g., processor 250) that is mounted on the package substrate(e.g., substrate 210 and/or device 301, 401 or 501). In fact, the jetcan be used to cool the processor that controls the jet (e.g., processor250).

In some cases, the airflow from embodiments of a synthetic jet device asdescribed herein (e.g., device 100, 301, 401 or 501) may be used invarious applications including (1) requiring a controlled airflow in anelectronic sensing device, especially where the requirement of smalltotal sensing solution exists, such as in wearables, smartphones,tablets, etc.; (2) sensing solutions for platform integration; (3)differentiation from novel sensing solutions integrated withinplatforms; (4) IoT standalone sensor solutions; or (5) microfluidicsmicro-scale pumping applications.

In some cases, the airflow from embodiments of a synthetic jet device asdescribed herein (e.g., device 100, 301, 401 or 501) may be used invarious applications including (1) a local thermal management solutionfor a processor; (2) other devices that require active cooling in smalland/or thin devices to meet ergonomic and/or component temperaturelimits for high power workloads.

FIG. 6 illustrates a computing device 600, such as a system on a chip(SoC), in accordance with some implementations. The computing device 600houses board 602. Board 602 may include a number of components,including but not limited to processor 604 and at least onecommunication chip 606. Processor 604 is physically and electricallyconnected to board 602, such as using or through a processor packagewhich may include a synthetic jet device as described herein (e.g.,device 100, 301, 401 or 501). In some implementations at least onecommunication chip 606 is also physically and electrically connected toboard 602, such as using or through a processor package which mayinclude a synthetic jet device as described herein (e.g., device 100,301, 401 or 501), as noted herein. In further implementations,communication chip 606 is part of processor 604.

In some cases, FIG. 6 illustrates a computing device 600 including asystem on a chip (SoC) 602, in accordance with one implementation. Insome cases, FIG. 6 shows an example of a system on a chip (SoC)technology (e.g., motherboard 602). Such a SoC may include amicroprocessor or CPU, as well as various other components, includingelectronics and transistors for power and battery regulation; radiofrequency (RF) processing, receipt and transmission; voltage regulation;power management; and possibly other systems such as those that may befound in a cellular telephone, etc. FIG. 6 may include one or moreadditional processors or chips mounted on board 602 or on anothercomponent such as a different card or PCB, such as using or through aprocessor package which may include a synthetic jet device as describedherein (e.g., device 100, 301, 401 or 501), as noted herein.

Depending on its applications, computing device 600 may include othercomponents that may or may not be physically and electrically connectedto board 602. These other components include, but are not limited to,volatile memory (e.g., DRAM), non-volatile memory (e.g., ROM), flashmemory, a graphics processor, a digital signal processor, a cryptoprocessor, a chipset, an antenna, a display, a touchscreen display, atouchscreen controller, a battery, an audio codec, a video codec, apower amplifier, a global positioning system (GPS) device, a compass, anaccelerometer, a gyroscope, a speaker, a camera, and a mass storagedevice (such as hard disk drive, compact disk (CD), digital versatiledisk (DVD), and so forth).

Communication chip 606 enables wireless communications for the transferof data to and from computing device 600. The term “wireless” and itsderivatives may be used to describe circuits, devices, systems, methods,techniques, communications channels, etc., that may communicate datathrough the use of modulated electromagnetic radiation through anon-solid medium. The term does not imply that the associated devices donot contain any wires, although in some embodiments they might not.Communication chip 606 may implement any of a number of wirelessstandards or protocols, including but not limited to Wi-Fi (IEEE 802.11family), WiMAX (IEEE 802.16 family), IEEE 802.20, long term evolution(LTE), Ev-DO, HSPA+, HSDPA+, HSUPA+, EDGE, GSM, GPRS, CDMA, TDMA, DECT,Bluetooth, derivatives thereof, as well as any other wireless protocolsthat are designated as 3G, 4G, 5G, and beyond. Computing device 600 mayinclude a plurality of communication chips 606. For instance, a firstcommunication chip 606 may be dedicated to shorter range wirelesscommunications such as Wi-Fi and Bluetooth and a second communicationchip 606 may be dedicated to longer range wireless communications suchas GPS, EDGE, GPRS, CDMA, WiMAX, LTE, Ev-DO, and others.

Processor 604 of computing device 600 includes an integrated circuit diepackaged within processor 604. In some implementations, the integratedcircuit die is packaged within, using or through a processor packagewhich may include a synthetic jet device as described herein (e.g.,device 100, 301, 401 or 501), as noted herein, thus providing morestable and increased cooling on a packaging substrate and/or processor,as noted herein, such as with reference to FIGS. 2-5. The term“processor” may refer to any device or portion of a device thatprocesses electronic data from registers and/or memory to transform thatelectronic data into other electronic data that may be stored inregisters and/or memory. In some cases, processor 604 may be a SoC.

Communication chip 606 also includes an integrated circuit die packagedwithin communication chip 606. In some implementations, this integratedcircuit die is packaged within, using or through a processor packagewhich may include a synthetic jet device as described herein (e.g.,device 100, 301, 401 or 501), as noted herein, thus providing morestable and increased cooling on a packaging substrate and/or processor,as noted herein, such as with reference to FIGS. 2-5.

In various implementations, computing device 600 may be a laptop, anetbook, a notebook, an ultrabook, a smartphone, a tablet, a personaldigital assistant (PDA), an ultra mobile PC, a mobile phone, a desktopcomputer, a server, a printer, a scanner, a monitor, a set-top box, anentertainment control unit, a digital camera, a portable music player,or a digital video recorder. In further implementations, computingdevice 600 may be any other electronic device that processes data.

EXAMPLES

The following examples pertain to embodiments.

Example 1 is a synthetic jet device comprising a vibrating membranedisposed between a top cavity and a bottom cavity; a lower supportdisposed between the membrane and a permanent magnet, the lower supporthaving a bottom surface coupled to a top surface of the permanent magnetaround a perimeter of the top surface of the permanent magnet; an uppersupport disposed between the membrane and a top lid, the upper supporthaving a top surface coupled to a bottom surface of the top lid around aperimeter of the bottom surface of top lid; and an opening through thelid to allow puffs of air or liquid to be expelled from the top cavitythrough the opening when the vibrating membrane vibrates.

In Example 2, the subject matter of Example 1 can optionally include,wherein the lower support has a top surface attached to a bottom surfaceof the membrane around a perimeter of the bottom surface of themembrane.

In Example 3, the subject matter of Example 2 can optionally include,wherein the upper support has a bottom surface attached to a top surfaceof the membrane around a perimeter of the top surface of the membrane.

In Example 4, the subject matter of Example 1 can optionally include,wherein the vibrating membrane comprises an electroplated conductor, hasa top surface forming a bottom surface of the top cavity and has abottom surface forming a top surface of the bottom cavity; wherein thelower support comprises a conductive material, and forms an outersurface of the bottom cavity below the vibrating membrane; wherein theupper support comprises a conductive material, and forms an outersurface of the top cavity above the vibrating membrane; wherein thepermanent magnet comprises a ferromagnetic material, has a top surfaceforming a bottom surface of the bottom cavity, and is electricallyinsulated from the vibrating membrane; wherein the top lid comprises aninsulator material, and has a bottom surface forming a top surface ofthe top cavity; and wherein the opening extends from a top surface tothe bottom surface of the lid.

In Example 5, the subject matter of Example 1 can optionally include,wherein the opening has a diameter to allow air or fluid to be sucked inand expelled to create puffs of output air or fluid at a velocity thatentrains surrounding air or fluid to create a synthetic jet of air orfluid with a net outflow of the puffs and entrained surrounding air orfluid, from the top cavity and out of the opening.

In Example 6, the subject matter of Example 1 can optionally include,wherein the opening is an orifice having a diameter that ispredetermined based on the volume of the cavity, the diameter of thevibrating membrane, and the thickness of the vibrating membrane; andwherein a Helmoltz frequency of the top cavity matches a resonantfrequency of the vibrating membrane.

In Example 7, the subject matter of Example 1 can optionally includefirst and second electronic contacts electrically coupled to a first anda second edge, respectively, of the vibrating membrane, for conductingan alternating current through the vibrating membrane.

In Example 8, the subject matter of Example 1 can optionally include asource of alternating current electrically connected to the membranethrough the first or second contacts; wherein the alternating currenthas a frequency and amount of current to cause the vibrating membrane tovibrate with a predetermined amplitude and at a predetermined frequency.

In Example 9, the subject matter of Example 1 can optionally include oneof an electrically insulating epoxy, an electrically insulatingadhesive, or an electrically insulating layer disposed between the lowersupport and the magnet; wherein the upper support, the membrane and thelower support are an electroplated copper material; and wherein the toplid is a solder resist material.

Example 10 is a package substrate comprising a plurality of layers ofdielectric material; a plurality of layers of conductive materialincluding a plurality of layers of conductive traces and conductive viasformed between the plurality of layers of dielectric material; and asynthetic jet device disposed within the package substrate and having amagnet; and some of the plurality of layers of conductive material andsome of the plurality of layers of dielectric material.

In Example 11, the subject matter of Example 10 can optionally include,wherein the plurality of layers of conductive traces and conductive viasare plated onto the plurality of layers of dielectric material; andwherein the synthetic jet device is disposed within the plurality ofconductive traces, conductive vias, and dielectric layers.

In Example 12, the subject matter of Example 11 can optionally include,wherein the synthetic jet device has a vibrating member that is aconductive material, has one edge coupled to a source of alternatingcurrent; and wherein the source of alternating current is a circuit orprocessor attached to the package substrate that includes the syntheticjet device.

In Example 13, the subject matter of Example 12 can optionally include,wherein the synthetic jet device is driven by the alternating current toprovide a pulsating flow of air into a millimeter or micrometer scaleair gap above an opening in the jet device to break up thermalboundaries in the gap.

In Example 14, the subject matter of Example 10 can optionally include,wherein a first electronic trace of the electronic traces is coupledthrough an electronic contact of the synthetic jet device to a firstedge of a vibrating membrane of the synthetic jet device; and wherein asecond electronic trace of the electronic traces is coupled through asecond contact to a second edge of the vibrating member, wherein thesecond edge is disposed opposite of the first edge.

In Example 15, the subject matter of Example 14 can optionally include aprocessor chip mounted onto a first surface of the package substrate,the processor chip having electronic contacts coupled to electroniccontacts on the first surface of the package substrate, the processorchip having a control circuit to transmit an alternating current as anelectrical driving signal to the first electronic trace of the packagesubstrate.

In Example 16, the subject matter of Example 15 can optionally include amotherboard mounted onto a second surface of the package substrate, themotherboard having electronic contacts coupled to electronic contacts onthe second surface of the package substrate.

In Example 17, the subject matter of Example 10 can optionally includethe synthetic jet device including a vibrating membrane disposed betweena top cavity and a bottom cavity; a lower support having a top surfaceattached to a bottom surface of the membrane around a perimeter of thebottom surface of the membrane; an upper support having a bottom surfaceattached to a top surface of the membrane around a perimeter of the topsurface of the membrane; wherein the magnet is a permanent magnet havinga top surface coupled to a bottom surface of the lower support around aperimeter of the top surface of the permanent magnet; a top lid having abottom surface attached to a top surface of the upper support around aperimeter of the bottom surface of the top lid; and an opening throughthe lid to allow puffs of air or liquid to be expelled from the openingwhen the vibrating membrane vibrates.

Example 18, is a method of forming a synthetic jet device; laminating afirst layer of dielectric material over a carrier substrate of a packagesubstrate; forming an opening in the first layer of dielectric materialfor a lower support of a vibrating membrane of the jet device; forming ametal lower support for the vibrating membrane in the opening; forming aconductive metal vibrating member on the first layer of dielectricmaterial and on the lower support, a perimeter of the member attached tothe lower support; forming a second layer of dielectric material on thevibrating member; forming an opening in the second layer of dielectricmaterial for an upper support of a top lid of the jet device; forming ametal upper support for the top lid in the opening; etching to removethe second layer of dielectric material from above the vibrating memberto form a top cavity above the vibrating member; separating the firstdielectric layer from the carrier substrate; etching to remove the firstlayer of dielectric material from below the vibrating member to form abottom cavity below the vibrating member; forming a top lid across a topsurface of the upper support to form the top cavity between the top lidand the top surface of the vibrating member, the top lid having anopening to allow puffs of air or liquid to be expelled from the topcavity through the opening when the vibrating membrane vibrates; andattaching a magnet across the bottom surface of the lower support toform the bottom cavity between the magnet and the bottom surface of thevibrating member.

In Example 19, the subject matter of Example 18 can optionally include,wherein forming the conductive metal vibrating member comprises formingthe conductive metal vibrating member so that a perimeter of the memberis attached to a top surface of the lower support; wherein the uppersupport is formed on one of the vibrating member above the lowersupport, or on a separate support adjacent to the lower support; andwherein forming the lid comprises one of forming a solder resist over alayer of conductor plated on the second layer of dielectric material orattaching a discrete lid to the upper support.

In Example 20, the subject matter of Example 18 can optionally include,wherein after forming the metal upper support and before etching toremove the second layer of dielectric material, further comprisingforming an upper metal layer on the second dielectric layer; formingopenings through the upper metal layer, etching through the openingsthrough the upper metal layer to remove the second dielectric layer;forming a solder resist over and covering the openings in the metallayer except for a single opening in the center of the metal layer; andcoating the solder resist with a hard mask to protect portions of thesolder resist during etching of the second layer of dielectric material.

In Example 21, the subject matter of Example 18 can optionally include,wherein laminating a first layer of dielectric material compriseslaminating two first layers of dielectric material over two opposingsurfaces of the carrier substrate; wherein forming the opening in thefirst layer of dielectric material for the lower support comprisesforming two openings for two lower supports of two vibrating membranesin the first layers; wherein forming the metal lower support comprisesforming two metal lower supports in the two openings for two jetdevices; wherein forming the conductive metal vibrating member comprisesforming two conductive metal vibrating members on the first layers andlower supports; wherein forming the second layer of dielectric materialon the vibrating member comprises laminating two second layers ofdielectric material over the two vibrating members; wherein forming theopening in the second layer of dielectric material comprises forming twoopenings for two upper supports of two top lids of the two jet devices;wherein forming a metal upper support for the top lid in the openingcomprises forming two metal upper supports for the two top lids; whereinetching to remove the second layer of dielectric material from above thevibrating member comprises etching to remove the two second layers ofdielectric material from above the two vibrating members to form two topcavities above the vibrating member; and wherein separating the firstdielectric layer from the carrier substrate comprises separating the twofirst layers of dielectric material from the two opposing surfaces ofthe carrier substrate.

It should also be appreciated that reference throughout thisspecification to “one embodiment”, “an embodiment”, “one or moreembodiments”, or “different embodiments”, for example, means that aparticular feature may be included in the practice of the embodiments.Similarly, it should be appreciated that in the description variousfeatures are sometimes grouped together in a single embodiment, figure,or description thereof for the purpose of streamlining the disclosureand aiding in the understanding of various inventive aspects ofembodiments. This method of disclosure, however, is not to beinterpreted as reflecting an embodiment that requires more features thanare expressly recited in each claim. Rather, as the following claimsreflect, inventive aspects of embodiments that may lie in less than allfeatures of a single disclosed embodiment. For example, although thedescriptions and figures above describe using a single jet device 100 insubstrate 210 is can be appreciated that 2, 3, 4, or a dozen suchdevices may be fabricated by a packaging formation process withinsubstrate 210, such as to cool substrate 210 and/or processor 250. Thus,the claims following the Detailed Description are hereby expresslyincorporated into this Detailed Description, with each claim standing onits own as a separate embodiment of the invention.

1. A synthetic jet device comprising: a vibrating membrane disposedbetween a top cavity and a bottom cavity; a lower support disposedbetween the vibrating membrane and a permanent magnet; an upper supportdisposed between the vibrating membrane and a top lid; and an openingthrough the lid.
 2. The device of claim 1, wherein the lower support hasa top surface attached to a bottom surface of the vibrating membranearound a perimeter of the bottom surface of the vibrating membrane. 3.The device of claim 2, wherein the upper support has a bottom surfaceattached to a top surface of the vibrating membrane around a perimeterof the top surface of the vibrating membrane.
 4. The device of claim 1,wherein the vibrating membrane comprises an electroplated conductor, hasa top surface forming a bottom surface of the top cavity and has abottom surface forming a top surface of the bottom cavity; wherein thelower support comprises a conductive material, and forms an outersurface of the bottom cavity below the vibrating membrane; wherein theupper support comprises a conductive material, and forms an outersurface of the top cavity above the vibrating membrane; wherein thepermanent magnet comprises a ferromagnetic material, has a top surfaceforming a bottom surface of the bottom cavity, and is electricallyinsulated from the vibrating membrane; wherein the top lid comprises aninsulator material, and has a bottom surface forming a top surface ofthe top cavity; and wherein the opening extends from a top surface tothe bottom surface of the lid.
 5. The device of claim 1, wherein theopening has a diameter to allow puffs of fluid to be sucked in andexpelled from the top cavity through the opening when the vibratingmembrane vibrates, to create the puffs of the fluid at a velocity thatentrains the fluid surrounding the synthetic jet device to create asynthetic jet of the fluid comprising the puffs of the fluid and theentrained surrounding fluid.
 6. The device of claim 1, wherein theopening is an orifice having a diameter that is predetermined based onthe volume of the top cavity, a diameter of the vibrating membrane, anda thickness of the vibrating membrane; and wherein a Helmoltz frequencyof the top cavity matches a resonant frequency of the vibratingmembrane.
 7. The device of claim 1, further comprising: first and secondelectronic contacts electrically coupled to a first and a second edge,respectively, of the vibrating membrane, for conducting an alternatingcurrent through the vibrating membrane.
 8. The device of claim 7,further comprising: a source of the alternating current electricallyconnected to the vibrating membrane through the first or secondelectronic contacts; wherein the alternating current has a frequency andamount of current to cause the vibrating membrane to vibrate with apredetermined amplitude and at a predetermined frequency.
 9. The deviceof claim 1, further comprising one of an electrically insulating epoxy,an electrically insulating adhesive, or an electrically insulating layerdisposed between the lower support and the magnet; wherein the uppersupport, the vibrating membrane and the lower support are anelectroplated copper material; and wherein the top lid is a solderresist material.
 10. The device of claim 1, wherein the fluid is atleast one of a gas or a liquid.
 11. A package substrate comprising: aplurality of layers of dielectric material; a plurality of layerscomprising dielectric material and conductive material includingconductive traces and conductive vias formed between the plurality oflayers of dielectric material; and a synthetic jet device disposedwithin the package substrate, the synthetic jet device having: a magnet;some of the plurality of layers comprising dielectric material andconductive material; and some of the plurality of layers of dielectricmaterial.
 12. The package substrate of claim 11, wherein the pluralityof layers including conductive traces and conductive vias are platedonto the plurality of layers of dielectric material; and wherein thesynthetic jet device is disposed within the plurality includingconductive traces, conductive vias, and dielectric layers.
 13. Thepackage substrate of claim 12, wherein the synthetic jet device has avibrating member that is a conductive material, has one edge coupled toa source of alternating current; and wherein the source of alternatingcurrent is a circuit or processor attached to the package substrate thatincludes the synthetic jet device.
 14. The package substrate of claim 13wherein the synthetic jet device is driven by the alternating current toprovide a pulsating flow of fluid into a millimeter or micrometer scalefluid gap above an opening in the synthetic jet device to break upthermal boundaries in the gap.
 15. The package substrate of claim 14,wherein the fluid is at least one of a gas or a liquid.
 16. The packagesubstrate of claim 11, wherein a first electronic trace of theelectronic traces is coupled through an electronic contact of thesynthetic jet device to a first edge of a vibrating membrane of thesynthetic jet device; and wherein a second electronic trace of theelectronic traces is coupled through a second contact to a second edgeof the vibrating member, wherein the second edge is disposed opposite ofthe first edge.
 17. The package substrate of claim 16, furthercomprising a processor chip mounted onto a first surface of the packagesubstrate, the processor chip having electronic contacts coupled toelectronic contacts on the first surface of the package substrate, andthe processor chip having a control circuit to transmit an alternatingcurrent as an electrical driving signal to the first electronic trace ofthe package substrate.
 18. The package substrate of claim 17, furthercomprising a motherboard mounted onto a second surface of the packagesubstrate, the motherboard having electronic contacts coupled toelectronic contacts on the second surface of the package substrate. 19.The package substrate of claim 11, the synthetic jet device including: avibrating membrane disposed between a top cavity and a bottom cavity; alower support having a top surface attached to a bottom surface of thevibrating membrane around a perimeter of the bottom surface of thevibrating membrane; an upper support having a bottom surface attached toa top surface of the vibrating membrane around a perimeter of the topsurface of the vibrating membrane; wherein the magnet is a permanentmagnet having a top surface coupled to a bottom surface of the lowersupport around a perimeter of the top surface of the permanent magnet; atop lid having a bottom surface attached to a top surface of the uppersupport around a perimeter of the bottom surface of the top lid; and anopening through the lid to allow puffs of fluid to be expelled from theopening when the vibrating membrane vibrates.
 20. The package substrateof claim 19, wherein the fluid is at least one of a gas or a liquid. 21.A system comprising: a package substrate having a plurality of layers ofdielectric material and a plurality of layers including conductivematerial; and a synthetic jet device disposed within the packagesubstrate, the synthetic jet device having: a vibrating membranedisposed between a top cavity and a bottom cavity; a lower supportdisposed between the vibrating membrane and a permanent magnet; an uppersupport disposed between the vibrating membrane and a top lid; and anopening through the lid.
 22. The system of claim 21, further comprising:first and second electronic contacts electrically coupled to a first anda second edge, respectively, of the vibrating membrane, for conductingan alternating current through the vibrating membrane.
 23. The system ofclaim 22, further comprising: a source of the alternating currentelectrically connected to the vibrating membrane through the first orsecond electronic contacts; wherein the alternating current has afrequency and amount of current to cause the vibrating membrane tovibrate with a predetermined amplitude and at a predetermined frequency.24. The device of claim 21, wherein the opening has a diameter to allowpuffs of fluid to be sucked in and expelled from the top cavity throughthe opening when the vibrating membrane vibrates, and wherein the fluidis at least one of a gas or a liquid.